Tractor-drive.



R. HUMPHHIES.

'TRACTOR DRIVE.

APPLICATION FILED JUNE I2. I9I8. 1,292,471. Patented Jan.28,1919.

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BEIGE.

RALPH HUMPI-IRIES, OF VANCOUVER, BRITISH COLUMBIA, CANADA.

TRACTOR-DRIVE.

Specification of Letters Patent.

Patented Jan. 28, 1919.

Application led I une 12, 1918. Serial No. 239,621.

To all whom t may concern:

Be it known that I, RALPH Huiiirriiiins, a citizen of the Dominion of Canada, residing at Vancouver, in the Province of British Columbia, Canada, have invented certain new and useful Improvements in Tractor- Drives, of which the following is a specification.

This invention relates to an improvement in the arrangement and mechanism of the driving wheels of a tractor by which an enlarged area of driving wheel contact with the ground is attained and that without imposing excessive friction on the driving mechanism and without materially interfering with the turning power of theveliicle.

Further, the pressure of the drivingcontact on the ground is increased proportionately with the traction imposed on the enine. g These results are attained by the mechanism set forth in the following specification, reference being made to the drawings by which itis accompanied, in which:

Figure 1 is a side elevation of the driving wheels of one side of the vehicle from the inner side, and

Fig. 2, a section on the line 22 in Fig. 1.

In these drawings 2 represents the frame of one side of the vehicle and 3 the main driving wheel of the same side. This wheel 3 is driven from the differential shaft 4: of the engine by a pinion 5, the teeth of which mesh with those of an internal gear 6 secured to the wheel 3.

A supplementary driving wheel 9 is mounted in front of the main driving wheel in bearing blocks 8 which travel in vertically disposed curved slots in frames 10 which are strongly secured to the inner adjacent sides of the frames 2. That the ground contacts of the wheels 3 and 9 may be brought as close together as practicable, ythe wheels are in different but parallel planes that their rims may overlap Vone another.

The supplementary wheel 9 is driven from the main driving wheel 3 by a chain 11 passing around a sprocket wheel 15 secured on the axle 7 of the supplementary driving wheel and one 12 secured on a short shaft 13 which is rotatably mounted in bearings secured to the frame 2 immediately below the axle of the main driving wheel, and is driven from that wheel by a pinion 14 secured on the shaft 13, the teeth of which pinion mesh with those of the internal gear 6 of the wheel.

The curve of the slot in which the bearings of the supplementary wheel axle rise and fall is struck from the center of the shaft 13 from which the wheel is driven that rise and fall of the supplementary wheel axle will not interfere with its chain drive.

The driving gear from the main driving whee1 3 to the supplementary driving wheel 9, which is. of relatively less diameter, is so proportioned as to give substantially the same speed at the circumference of the two wheels.

With this supplementary drive wheel 9 the tractor has an increased ground contact for tractive purposes without materially extending tlie driving wheel base, so that the vehicle can turn on a comparatively small radius.

In order that the supplementary driving wheel 9 may be drawn more tightly into contact with the ground when a greater tractive effort is required, the draw bar 16 is exibly connected by chains 17 which pass around sheaves 18 and are connected to them at 19. These sheaves 18 are free torotate on the shaft 7 of the supplementary driving wheel and to each sheave is connected a geared sector 20. the teeth of which mesh with those of a geared segment 21 secured to and downwardly projecting from the frame 2 of the vehicle. These segments 20 may conveniently form a part of the frames 10 in which are the curved slots, as affording mutual support.

The draw bar 16 is preferably connected to a forked lever 22 mounted at 23 between the frames 2, and the flexible connections 17 of the two sheaves 18 are connected to bifurcated ends of this lever 22.

With this arrangement the supplementary driving wheel is directly drawn into contact with the ground by the pull of the draw bar and the fact that the tread of the supplementary wheel is on a different track to that of the main driving wheel will afford a better driving contact with the ground and be less liable to sink in soft ground. Further, the tread of the two wheels being as close as practicable together will facilitate turning of the vehicle.

I do not desire to be conlined to the exact construction here set forth of increasing the pressure on the supplementary driving wheel by the pull of the draw bar where the wheels are in direct contact with the ground, asthe same may be varied within* wide limits,f but consider my invention to reside in any means whereby the pull of the draw bar willA` increase the pressure on a supplementary driving wheel in direct contact with the ground,

whether said wheel is mounted inaidvancev of or behind the main driving wheel and;

whether it is drawn down by the curved rack and pinionv or otherwise.

Having now particularly described my in-v vention, ll hereby declarethat what I claim as` new l nd desire to` be protected in byLetters Batent, is:

l. In a tractor drive, the combination with amain driving wheel in direct contact with the ground aI supplementary drivingwheel in similar direct contact with the groundk but' having provision `whereby` it may rise and` fall in 'relation to the main driving wheel, and meansA operableA by. the;

pull of the draw bar forV pressing, the s upplementary driving wheel into tighter. contact with the ground as the pull on the draw bar is increased.

2. A tractor drive, comprising the coms bination with a main driving' wheelgin direct contact with the ground', a supplementary wheel in similar direct contact, whichsupplementary wheel is driven from the main driving wheel7 the supplementary wheel having provision ,whereby it mayY rise and fall. in relation to the main driving wheelgfwhile retaining its. driving relation therewith, and.

means operative by the pull of the draw bar for pressing the/supplementary wheel into. closery contact with the ground as the pullv onthe draw bar increases. V

3. A tractor drive, comprising the combinati'on lwith a main drivingyvvheel in direct Contact witlrthe ground-"asupplemen tary wheel in similar direct contact and driven from the main driving Wheel, the aiilesvof thenwheels being as close as practicable ltogether planes ofnlotatica, the Supplementary Wheel having provision whereby it may rise and fall in relation toL the (fil-'iviiag-VVV Wheel",`

andansans2 Opelwtreby the .pull otthedi'aw" bar; for pressing. thesupplementary wheel into clsen ccntact' with the, gmini@ as: the. pull entire-draw bar-nleaseev' i' 4:, a tractor. drive, Commis., gfthe; C Ombif nation withl a; main driving: wheel Y' in direct contact with Vthe ground, a supplementary. driving. wheel in similar directl Contact, which supple n lentaryi,` wheel? isf. driven from the maiirdriving. wheel the siipplpernentarywheel having provisionA wherebyit rise andf fall in relation tot` the main. driving in parallel but. 'diffr'ent In testimony @whereof I aflix my signature;

RALPH HUM-Pinares;-

Comee ci.V thsfpatentmey be obtained; for ve cents each, by adressingltne!=l.egane eg ,1pmm,

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